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An anonymous reader writes "According to new study published in Nature (abstract), MIT researchers have figured out how to trigger specific memories in rats by hitting certain neurons with a pulse of light. From the article: 'The researchers first identified a specific set of brain cells in the hippocampus that were active only when a mouse was learning about a new environment. They determined which genes were activated in those cells, and coupled them with the gene for channelrhodopsin-2 (ChR2), a light-activated protein used in optogenetics. ... The light-activated protein would only be expressed in the neurons involved in experiential learning — an ingenious way to allow for labeling of the physical network of neurons associated with a specific memory engram for a specific experience. Finally, the mice entered an environment and, after a few minutes of exploration, received a mild foot shock, learning to fear the particular environment in which the shock occurred. The brain cells activated during this fear conditioning became tagged with ChR2. Later, when exposed to triggering pulses of light in a completely different environment, the neurons involved in the fear memory switched on — and the mice quickly entered a defensive, immobile crouch.'"

It has become clear to me that editors and submitters both have cells tagged with ChR2 pretty much at random, and typing seems to engage triggering pulses of light.

We are all part of the experiment, I think it's to see who is the last one to give up waiting for quality to improve.

I'm going to read one more summary and if it sucks I'm done. Well that was obviously a dud, I'll give it a pass and the next one will determine it. Wait, that was idle, I'll see what the next one has...

An angry group of foreign citizens have surrounded the American Embassy in Egypt. All hope is lost. Suddenly, a flash of light from the roof - and everyone falls over vomiting and crying as they think about that one time they saw their parents fucking.

While I have no doubt that some aspiring psychologist and neurosurgeons would work to create a read/write memory machine for the purposes of treating PTSD, (memory can't trigger if the memory is destroyed. Patient lives a happier and more normal life), it would only be a short jump for the tech on say, DARPA's hands, and you have more of a Universal Soldier type situation, and from there, real, genuine thought police.

Personally though, I look at this in the light of yesterday's news about microtubule struct

Psychologists and patients can get by with VR simulations using a VR glasses and a powerful gaming PC. They just ctrate a game map that resembles the experience that gave the patient PTSD and gradually increase the realism. They can also create regular street scenes with car engines backfiring, motorists yelling, construction workers running machinery and dropping crates. Gradually they desensitize the patients to these stimuli.

I like the way you think. Color outside the box? What box! A technology such as this could have many positive applications as well. Need to learn how to fly a helicopter in an emergency? Flash. Done. It is a good question whether skills can be evoked in the same manner these experimenters have activated memories.

Did you see this one that hypothesizes that modifications to microtubules inside neurons are the mechanism for memory (and possibly computation), with each neuron possibly storing many "bytes" of information?

Thanks for that! I'd remembered seeing a reference to it, but hadn't found the original article and couldn't find where I'd seen the original reference. However memory works, I need an upgrade. A 16K expansion pack should suffice.

Now, if the neuron can indeed be coded this way, it would explain why just a few rat neurons can handle a flight simulator just fine. It would also explain why current models of biological neurons always fell short of reality -- as most models had assumed neurons stored a single st

Later, when exposed to triggering pulses of light in a completely different environment, the neurons involved in the fear memory switched on — and the mice quickly entered a defensive, immobile crouch.

This does not sound convincing to me at all - there could be many reasons for the mouse to become defensive, one of the least likely of which is that a specific memory was triggered...

Luckily, you're dealing with Science, not armchair philosophers or youtube commentators. I appreciate your attempt at using logic, but don't trust the summary to explain everything. From the abstract, it seems Science has considered that you might have a point, and went back in time to address it.

The mice showed increased freezing only upon light stimulation, indicating light-induced fear memory recall. This freezing was not detected in non-fear-conditioned mice expressing ChR2 in a similar proportion of

Rats will go into a defensive crouch pretty much at any sudden unexpected stimulus. Put an electrode into a pleasure center and activate it and the rat will go into a defensive crouch. You see this all the time when shaping in skinner boxes.

It would be very hard to say that they were re-experiencing that specific memory.

Referring to the 17th-century French philosopher who wrote, "I think, therefore I am," Tonegawa says, "Rene Descartes didn't believe the mind can be studied as a natural science. He was wrong. This experimental method is the ultimate way of demonstrating that mind, like memory recall, is based on changes in matter."